Installation for the continuous casting of non-ferrous metals in a protective gas atmosphere

ABSTRACT

An installation for the continuous casting of non-ferrous metals in a protective gas atmosphere, comprising a mixing chamber for a liquid metal; an open-bottomed chamber filled with a protective gas and which is positioned below and hermetically connected to the mixing chamber; a mold reciprocably positioned in the openbottomed chamber and adapted to be reciprocated with respect to an ingot being extracted therefrom and with respect to the chamber. A vessel of varying shape and made from an elastic material is connected to the open-bottomed chamber so as to maintain the pressure of the protective gas in the latter above the surface of the liquid metal in the mold at a height not exceeding 3 mm of water column.

United States Patent [1 1 Kashnba et al.

[111 3,833,050 [451 Sept. 3, 1974 Feichtinger 75/59 INSTALLATION FOR THE CONTINUOUS 2,997,384 8/1961 CASTING 0 NONJERROUS METALS IN Ewen l PROTECTIVE GAS ATMOSPHERE 3:402:757 9/1968 l64/28l [76] Inventors: Vladimir Pavlovich Kashuba, ulitsa 3,482,621 12/1969 l-lalliday 164/259 X Lenina, 40, kv. 42; Nikolai Pavlovich Mikhailov, ulitsa FOREIGN PATENTS OR APPLICATIONS Mat osova 15 kv Lev 781,277 8/l957 Great Britain 164/66 Petrovich Fridman, ulitsa Frunze 891,444 9/1953 Germany 164/273 13, kv. 16, all of Balkhash; Vadim Nikolaevich Rattenberg, ulitsa Primary ExaminerJ. Spencer Overholser Sedova, korpus l, kv. 31, Moscow, Assistant Examiner'-V. K. Rising all of USSR. Attorney, Agent, or Firm-Waters, Roditi, .Schwartz & 22 Filed: Mar. 29, 1972 M856 [21] Appl. No.: 239,092 ABSTRACT I l UT App-cation Data An installation -for. the continuous casting of hen- [631' Contmuation-m-part of Ser. No. 833,954, June l7, ferrous metals in avprotective gas atmosphere I968 abandoned prising a mixing chamber for a liqnidlmetal; anopenbottomed chamber filled with a protective gas and [52] Cl 164/281 164/259 5 which is positioned below and hermetically connected 51 I t Cl v 822d 11/00 to the mixing chamber; a mold reciprocably posid 66 83 273 tioned in the open-bottomed chamber and adapted to 1 earc l 64/64281 82 be reciprocated with respect to an ingot'being ex tracted therefrom and with respect to the chamber. A vessel of varying shape and made from an elastic ma- [56] -References Cited terial is connected to the open-bottomed chamber so UNITED STATES PATENTS as to maintain the pressure of the protective gas in the 1,839,106 12/1931 Loth 165/259 latter above the surface of the liquid metal in the mold 2,761,002 8/1956 Laird et al. 164/259 at a height not exceeding 3 mm of water column 2,825,104 3/1958 Jones 164/83 X I 2,905,989 9/1959 Black l64/28l X vl Claim, l-Drawing Figure Z 4 a 7 Z 5 \JOOO 1 I INSTALLATION FOR THE CONTINUOUS CASTING OF NON-FERROUS METALS IN A PROTECTIVE GAS ATMOSPHERE of non-ferrous metals in a protective gas atmosphere.

The present invention can be most successfully used for producing ingots of oxygen-free copper.

Known in the prior art are installations for the continuous casting of non-ferrous metals in a protective gas atmosphere, which include a chamber filled with a protective gas, through which liquid metal is conveyed into a mold which is disposed therebelow, and with the mold being reciprocated with respect to an ingot being extracted therefrom, and with respectto the chamber.

An indispensable condition for obtaining a highquality ingot from a non-ferrous metal consists of in that the metal should be conveyed into the mold without excessively oxidized. This is achieved in that liquid metal is conveyed into the mold by being passed through a chamber which is filled with a protective gas containing not more than 0.1 percent oxygen.

However, during this operation the mold reciprocates so as to act as a plunger pump and thereby continuously varying the pressure exerted on the surface of liquid metal.

When moving downwardly the mold sucks in air through untight locations thus enriching the atmosphere above the surface of liquid metal so as'to be conducive to an oxidation of the latter and to the formation of a low-quality ingot.

Consequently, an excessive amount of protective gas must be constantly supplied into the chamber, thereby resulting in a high rate of consumption of this gas.

Also known from West German Patent No. 891,444 is an installation which includes molds and a V-shaped vessel which is filled with a working liquid, and which maintains a constant pressure in the space above the surface of the metal located in the mold.

However, in the continuous casting installations in which the molds reciprocate at high speeds, it is impossible to employ a V-shaped vessel because of the following reasons:

Due to a retarding inertial action, the working liquid in the V-shaped vessel will move at a frequency and amplitude which are different from the reciprocation of the mold, as a result of which there takes place an additional variation in the pressure in'the space above the surface of liquid metal in the mold. Additionally, the necessity of decreasing the resultant extent of displacement of the working liquid in the V-shaped vessel requires the provisionof bulky V-shaped vessels which are not particularly reliable in operation.

An object of the present invention is to provide an installation for continuous casting which renders it possible to create an oxygen-free atmosphere in the chamber which is filled with a protective. gas.

Another object of the present invention is to provide an installation for continuous casting which ensures a lower rate of consumption of the protective gas.

gas atmosphere pressure above the surface of liquid metal in the mold at a height-not exceeding 3 mm of water column.

These and other objects ofthe present invention are attained in that an installation for the continuous casting of non-ferrous metals in a protective gas atmosphere is provided with a mixing chamber for liquid metal; an open-bottomed chamber filled with a protec tive gas and hermetically connected to the mixing chamber; a mold located in the open-bottomed chamber and being vertically reciprocable therein with respect to an ingot being extracted therefrom and with respect to the open-bottomed chamber; a vessel connected with the open-bottomed chamber, the vessel having a varying shape and being made from an elastic material so as to be adopted to maintain the pressure of the protective gas atmosphere above the surface of liquid metal in the mold at a height not exceeding 3 mm of water column.

The following description of an exemplary embodiment of the present invention is given with reference to the single Figure in the accompanying drawing which shows a partly schematic view of the installation in longitudinal section. I

The installation for the continuous casting of nonferrous metals in a protective gas atmosphere comprises an open-bottomed chamber ,1 which is filled with a protective gas. The upper part of the chamber is provided with an annular sand-filled channel 2 fonning a so-called sand seal between the chamber 1. and a superimposed delivery' box which includes a liquid metal mixing. chamber 3 providedwith a hole '4 for tapping liquid metal. 7 Y

A peep hole 5 is provided on one side of the chamber 1 so as to allow observation of the level of liquid metal in a mold 6 disposed in the lower part of the chamber 1. At the opposite side of the chamber 1 there is connected a pipeline 7 which communicates the interior of the chamber 1 with a vessel 8. The vessel 8 is of a varying shape and made from an elastic material, such as rubber. Variation in the volume of the vessel makes it possible to maintain the protective gas atmosphere pressure above the surface of liquid metal in the mold 6 at a height'not exceeding 3 mm of water column. If the pressure were to be higher, the quality of the ingots would be adversely affected, and the rate of consumption of the protective gas increased.

Connected to chamber 1, at a location lower than the pipeline 7, is a pipeline 9 which is employed for introducing a protective gas into the chamber 1.

Mountedon the mold 6 is an annular guide sleeve 10 having an annular seal 11 extending thereabout so as to form a sliding seal between the mold v6-and chamber 1-. The mold 6 is vertically reciprocated relative to-.the ingot and chamber by means of any suitable actuating device (not shown). I I

The installation operates as follows.

Through the hole 4 liquid metal is cast 'into mold 6 from mixing chamber 3 by being transmitted through the chamber 1 which is filled with a protective gas. The mold 6 is vertically reciprocated (is shown by .the arrows) with respect to an ingot being extracted therefrom, with the liquid metal solidifying in the mold and being extracted therefrom as a finished ingot..

When the mold 6, together with the guide sleeve and seal 11, is reciprocated with respect to the chamber l, the pressure in the latter does not vary due to the gas flow into and out of the vessel 8, responsive to the varying shape and elastic material construction of the latter. When the pressure in the chamber 1 increases the vessel 8 takes in the excessive protective gas, and ejects it when the mold 6 moves downwardly in the open-bottomed chamber 1.

Hence, the installation according to the present invention excludes the suction of air into the protective gas-containing chamber during the casting operation, maintains the pressure of the protective gas above the surface of liquid metal in the mold within predetermined limits, allows formation of a high-quality ingot of a non-ferrous metal, and enables an appreciable reduction in the consumption of the protective gas.

What is claimed is:

1. An installation for the continuous casting of nonferrous metals in a protective gas atmosphere, comprising: an open-bottomed vertical chamber; a delivery box for conveying said non-ferrous metals in a liquid state into the upper end of said chamber, said delivery box being positioned above said chamber and hermetically connected thereto with respect to the surrounding atmosphere; mold means being positioned within said chamber and vertically reciprocable relative to said chamber and concurrently with respect to an ingot of said metals being extracted from its lower end, said mold means extending downwardly through the open bottom of said chamber; means extending about said mold forming a slidable seal between said mold and being in sealing engagementwith the interior said chamber; means for filling said chamber, above the upper end of said mold means with 21 protective gas; and a separate closed elastic material vessel of variable shape and volume communicating with said chamber through an opening through the wall of said chamber above the upper end of said mold means for maintaining the pressure of the protective gas atmosphere vin said chamber above the surface of the liquid metal in said mold means at a height not exceeding 3 mm of water column. 

1. An installation for the continuous casting of non-ferrous metals in a protective gas atmosphere, comprising: an openbottomed vertical chamber; a delivery box for conveying said nonferrous metals in a liquid state into the upper end of said chamber, said delivery box being positioned above said chamber and hermetically connected thereto with respect to the surrounding atmosphere; mold means being positioned within said chamber and vertically reciprocable relative to said chamber and concurrently with respect to an ingot of said metals being extracted from its lower end, said mold means extending downwardly through the open bottom of said chamber; means extending about said mold forming a slidable seal between said mold and being in sealing engagement with the interior said chamber; means for filling said chamber above the upper end of said mold means with a protective gas; and a separate closed elastic material vessel of variable shape and volume communicating with said chamber through an opening through the wall of said chamber above the upper end of said mold means for maintaining the pressure of the protective gas atmosphere in said chamber above the surface of the liquid metal in said mold means at a height not exceeding 3 mm of water column. 